“The Lucas critique, named for Robert Lucas's work on macroeconomic policymaking, argues that it is naive to try to predict the effects of a change in economic

“The Lucas critique, named for Robert Lucas's work on macroeconomic policymaking, argues that it is naive to try to predict the effects of a change in economic policy entirely on the basis of relationships observed in historical data, especially highly aggregated historical data.“ - wiki This was pretty much proven for stocks too